The invention relates to a device for use with a sliver coiler. More particularly, the invention relates to a coiler plate for sliver coil deposits on, for example, draw frames, carding machines and the like. The coiler plate comprises a spatially curved sliver channel with a sliver inlet and a sliver outlet. The inlet is arranged next to, or coaxial with, the rotational axis and the outlet is arranged at a radial and axial distance from the inlet. The running sliver is subjected to a tensioning draft (force) and movement relative to the inside wall of the sliver channel. A frictional resistance exists between the sliver and the inside wall of the sliver channel.
In practical operations, the sliver in the sliver channel is subjected to multiple movement and force effects. The sliver experiences a certain slacking draft between withdrawing rollers, that pull the sliver after it is formed, and the moving can. A tensile force moves the sliver from the inlet, through the sliver channel, and to the outlet. The outlet is arranged at an axial distance to the inlet, thus causing the sliver to be additionally acted upon by a centrifugal force because of the rotational movement. This force results in a bulging of the sliver path and can lead to an undesirable draft. The centrifugal force is counteracted by reducing the distance between the curved sliver channel and the rotational axis, resulting in the inside wall exerting a counter force onto the sliver and reducing the bulging. The counter force, however, results in increased friction between the sliver material and the inside wall and reduces the sliver movement speed. Thus, undesirable drafts caused by friction cannot be ruled out.
A coiler plate design for delivery speeds of up to 1000 m/min with a curved sliver channel of polished stainless steel has been used. However, a permanent increase in the sliver speed above 1000 m/min was not possible with this design. High frictional forces between the inside wall and sensitive draw frame slivers, in particular, resulted in undesirable drafts.
Thus, it is an object of the invention to create a coiler plate of the aforementioned type, which avoids the previously mentioned disadvantages and, in particular, results in an improved sliver guidance and sliver quality.
Particular embodiments of the invention provide a coiler plate for sliver coil depositing. The coiler plate has a rotational axis, a spatially curved sliver channel having a wall, an inside wall surface, a sliver inlet, a sliver outlet, and a plurality of air inlets in the sliver channel wall for introducing air into the sliver channel. The sliver inlet is arranged substantially coaxial with the rotational axis, and the sliver outlet is arranged at a radial distance and an axial distance from the sliver inlet. The sliver is subject to a tensioning draft, and the air introduced into the sliver channel is for acting on the sliver to reduce a frictional force between the sliver and the inside wall surface of the sliver channel.
The measures according to the invention take into account the effects of different movements and forces exerted by the sliver and onto the sliver on the inside of the sliver channel. The forces are not effective in the same way at all locations. As a result, undesirable or interfering forces can be countered partially and individually by changing the interaction and/or the spatial correlation between the sliver and the inside wall. In this way, the sliver guidance and the sliver quality can be improved considerably and a substantial increase in the sliver running speed above 1000 m/min can be achieved. These speeds are particularly suitable for draw frames. The improved sliver guidance according to the invention in the same way permits an increase in the sliver quality, even for sliver running speeds below 1000 m/min. These speeds are particularly suitable for carding machines. In particular, the sliver draft is noticeably more uniform in its various sections or regions. The partial drafts and their effects on the sections or regions of the sliver in the sliver channel are more uniform and the tensioning draft is improved on the whole.